This invention relates to a laser light transmitting probe, which transmits laser light to living tissue of an animal such as a human body to permit an incision, vaporization of the living tissue or a thermal therapy.
Medical treatments such as incisions of living tissue of animal organisms by irradiation with laser light have become common due to the ability thereof to concurrently provide hemostasis.
It had been conventional that the laser light was irradiated from the fore end of an optical fiber which is held back out of contact with the living tissue. But this method causes severe damage to the fore end portion of the optical fiber. Therefore, a method which has been utilized lately is as follows; at first, the laser light, after being transmitted into an optical fiber system, is fed into a transmitting probe being brought into contact with or being held out of contact with the living tissue (hereafter "living tissue" is sometimes expressed by "tissue" only). Then the laser light emitted from the surface of the probe is irradiated on the tissue.
The inventor developed many kinds of contact probes which are utilized for various purposes. One embodiment is shown in FIG. 15. This probe 50 is made of sapphire, quartz and the like, and usually, its fore end portion is tapered and conical shaped uniformly.
However, referring to FIG. 15, laser light L is fed by means of an optical fiber 51 into the probe 50, which is of long and narrow conical shape with a round tip end and whose outer surface is smooth. The laser light L passing through the probe 50 is reflected and refracted on an inner surface to reach the tip end, finally is emitted from the tip end.
This conventional probe produces a power density and power distribution of the laser light L as shown as contour lines H and curve Pd, respectively, in FIG. 15. Accordingly, it is obvious that the laser light L is concentratedly emitted from the tip end of the probe 50. Therefore, the effective area of the laser light irradiation is very small and exists only in living tissue adjacent to the inserted portion of the probe.
On the other hand, when medical operations are carried out, various surgical treatments such as an incision, vaporization, an exfoliation of the tissue and occasionally hemostasis for ulcerated tissue are required.
In these prior art procedures, the exfoliation can not be carried out by the laser light irradiation, thus, only mechanical incisions have been applied. Further, when the large target area having ulcerated tissue is exfoliated, a medical cutter must be moved many times little by little.